I. 802.11 Wireless Network Standards Almost all laptops now contain Wi-Fi capability and wireless connectivity for computers is thus well established. The IEEE 802.11 standard, also referred to as Wi-Fi is now an accepted standard for WLAN solutions that are available. Wi-Fi is able to compete well with wired systems because operating speeds of systems using the IEEE 802.11 standards of around 54 Mbps is now common. Wi-Fi hotpots are found in abundance and in common use due to the flexibility and performance of the system.
Laptop computers can be now used while waiting in hotels, airport lounges, cafes, and other places using a wireless link rather than using a cable. Besides being used for temporary connections, and for temporary Wireless Local Area Network, WLAN applications, the 802.11 standards can also be used for more permanent installations. WLAN equipment can be used in offices to provide semi-permanent WLAN solutions. WLAN equipment use enables offices to be set up without requiring permanent wiring, which results in a considerable cost saving. WLAN equipment allows changes to be made around the office without the need to re-wiring. Due to this the Wi-Fi IEEE 802.
11 standard is used commonly to provide WLAN solutions both for temporary connections in hotspots in cafes, airports, hotels and similar places and also within office scenarios. All the 802.11 Wi-Fi standards operate within the ISM (Industrial, Scientific and Medical) frequency bands. License is not required for operation within these frequencies, and these are shared by a variety of other users which makes them ideal for a general system for widespread use. II. 802.11a,802.
11b, 802.11g, 802.11n & 802.11ac: A number of bearer standards that are in common use. Each standard was launched at different times and have different features. 802.11 is the collection of standards setup for wireless networking.
The most common and popular standards out of these are 802.11a, 802.11b, 802.11g, 802.11n and 802.
11ac providing raw data rates of up to 600 Mbps. A frequency is used by each standard to connect to the network which has a defined upper limit for data transfer speeds. 802.
11a was one of the first wireless standards. 802.11a can achieve a maximum of 54Mbps and operates in the 5Ghz radio band.
It was not as popular as the 802.11b standard due to higher prices and lower range. It operated in the 5 GHz ISM band rather than the 2.4 GHz band, which made chips more expensive and never caught on in the same way as 802.11b even though it offered a much higher data transfer rate.
Pros of 802.11a: Fast maximum speed; regulated frequencies prevent signal interference from other devices. Cons of 802.11a: Highest cost; shorter range signal that is more easily obstructed. 802.11b supports up to 11 Mbps and operates in the 2.4Ghz band.
It has a theoretical range of up to several hundred feet. It was the first real consumer option for wireless and very popular. 802.
11b uses the CSMA/CA technique for transmitting data, that was defined in the original 802.11 base standard and retained for 802.11b. With this technique, when a node has to make a transmission it listens for a clear channel and then transmits. Then it looks for an acknowledgement and if not received it holds back for a random time period, assuming interference is caused by another transmission, and then listens for a clear channel and then retransmits the data. Pros of 802.
11b: Cost is among lowest; has a good signal range and not easily obstructed. Cons of 802.11b: Maximum speed is among slowest; home appliances could interfere on the unregulated frequency band. 802.11b/g channels in 2.4GHz band: 802.
11g – While operating on the 2.4 GHz ISM band in order to provide the higher speeds of 802.11a, a new standard was introduced – known as 802.11g, it soon took over from the b standard. 802.11g uses the 2.
4 GHz frequency for greater range and supports bandwidth up to 54 Mbps. Since it operates in the same band as 802.11b, 802.11g is backward compatible with 802.11b, so that 802.
11g access points will work with 802.11b wireless network adapters and vice versa. 802.11a is not directly compatible with 802.11b or 802.11g since it operates in a different band.
The 802.11b standard became the most popular operating in the 2.4 GHz ISM band post the introduction of Wi-Fi with the 802.11a and 802.11b standards. This standard became the most popular despite the faster operating speed of 802.11a because the cost of producing chips to operate at 2.
4 GHz were much less than ones to run at 5 GHz. Pros of 802.11g: Fast maximum speed; signal range is good and not easily obstructed. Cons of 802.11g: Costs more than 802.11b; appliances may interfere on the unregulated signal frequency. 802.11n – Wireless network bearer has up to 600 Mbps data rates and operating in the 2.
4 & 5 GHz ISM bands. After establishing the Wi-Fi standards of 802.11a, 802.
11b, and 802.11g, efforts were begun to look at how raw data speeds provided by Wi-Fi, 802.11 networks could be increased more. As a result in January 2004 the IEEE announced forming a new committee to develop the new high speed, IEEE 802.11n standard.
In early 2006, the industry mostly agreed about the features for 802.11n. The standard soon became widespread with many products offered for sale and use with the improved performance offered by 802.11n. Although initially few Wi-Fi hotspots offered the standard, 802.
11n devices were compatible and able to work with the 802.11b and 802.11g based hotspots. Also referred to as “Wireless N”, 802.11n was designed to improve on 802.
11g in the amount of bandwidth supported by utilizing multiple wireless signals and antennas (called MIMO technology) instead of one. 802.11n was ratified by industry standards groups in 2009 with specifications providing for up to 300 Mbps of network bandwidth. Better range over earlier Wi-Fi standards was offered by 802.11n due to its increased signal intensity, and it is backward-compatible with 802.11b/g gear.
Pros of 802.11n: Fastest maximum speed and best signal range; more resistant to signal interference from outside sources. Cons of 802.11n: Costs more than 802.11g; the use of multiple signals may greatly interfere with nearby 802.
11b/g based networks. 802.11ac – The newest generation of Wi-Fi signaling in popular use, 802.
11ac utilizes dual-band wireless technology, supporting simultaneous connections on both the 2.4 GHz and 5 GHz Wi-Fi bands. 802.
11ac offers backward compatibility to 802.11b/g/n and bandwidth rated up to 1300 Mbps on the 5 GHz band plus up to 450 Mbps on 2.4 GHz.
The standard was developed from 2008 (PAR approved 2008-09-26) through 2013 and published in December 2013 (ANSI approved 2013-12-11). III. 802.12-IEEE Standards for Local and Metropolitan Networks: Demand Priority Access Method,Physical Layer and Repeater Specification for 100 Mb/s Operation Scope: The standard covers the protocol & compatible interconnection of data communication equipment via a repeater-controlled, star-topology Local Area Network (LAN) using the demand-priority access method. Purpose: To provide a higher LAN speed with deterministic access, optional filtering and priority. Demand priority is the media access control protocol used by the new 100 Mb/s 100 VG-AnyLAN network being standardised by the IEEE 802.12 committee. The network can interconnect hubs in multiple wiring closets (without bridging or routing), and can have a network diameter of several kilometers.
The IEEE 802.12 standard, called 100VG-AnyLAN is intended to provide a high-speed network that can operate in mixed Ethernet and Token Ring environments by supporting both frame types. The IEEE 802.x specifications are a group of network standards defined by ISO. 802.
12 covers the low level – Data Link Layer. The Data Link Layer is divided into 2 sublayers: i) LogicalLink Control (LLC). This sublayer establishes the transmission paths betweencomputers on a network.ii) MediaAccess Control (MAC).
On a network, the network interface card (NIC) has anunique hardware address which identifies a computer or peripheral device. Thehardware address is utilized for the MAC sublayer addressing. The IEEE 802.12 100 VG – AnyLAN is a high-speed network with a data rate of 100 megabits per second (Mb/s) which can be transmitted over several types of twisted pair cable including single or multiple mode fiber optic cable.
The 100VG-AnyLAN data packets can be encapsulated by IEEE 802.5 Token Ring or IEEE 802.3 Ethernet frames. The packets can also be routed across FDDI, ATM, and wide area networks. For media access, a packet is formatted with a training frame that is initially utilized by the IEEE 802.12 interface.
This initialization determines whether the packet is normal or high priority (for example, multimedia video or audio data) according to the Demand Priority Access Method media protocol (DPAM). IV. IEEE 802.13 – not used due to the number 13 beingconsidered superstitious. V.
The IEEE 802.14 – Cable modems. Defined in 1996, deals with digital transmission of cable TV networks.
Withdrawn PAR. It is not endorsed by the IEEE any more. In the 1990s a subcommittee (802.
14) was formed to develop a standard for cable modem systems. IEEE 802.14 developed a draft ATM-based standard. But, the 802.14 working group was disbanded as North American multi system operators (MSOs) instead supported the then fledgling DOCSIS 1.0 specification, which mostly used best efforts service and was IP-based (having extension codepoints to support ATM for QoS in the future).
MSOs wanted to quickly deploy service to compete for broadband Internet access customers instead of waiting on the slower, iterative, and deliberative processes of standards development committees. VI. The IEEE 802.15 The Wireless Personal Area Networks (WPANs) is covered by this group – Communications specification that was approved in early 2002 by the IEEE for wireless personal area networks. Different technologies are covered by several subgroups: 802.15.1 – Bluetooth based.
Short range (10m) wireless technology for cordless keyboard, mouse, and hands-free headset at 2.4 GHz. 802.15.3a – To provide a higher speed Ultra wideband (UWB) PHY enhancement amendment to IEEE 802.
15.3 for applications which involve imaging and multimedia. Short range, high-bandwidth “ultra wideband” link.
This was withdrawn in January 2006 802.15.4 – ZigBee. Short range wireless sensor networks.
IEEE 802.15.4 is a technical standard covering the operation of low-rate wireless personal area networks (LR-WPANs). This standard was defined in 2003 and maintained by the IEEE 802.
15 working group, it covers the physical layer and media access control for LR-WPANs. It forms the basis for the ZigBee ISA100.11a, WirelessHART, MiWi, SNAP, & Thread specifications, each of which further extends the standard by developing the upper layers which are not defined in IEEE 802.15.4.
It can also be used with 6LoWPAN, the technology used to deliver the IPv6 version of the Internet Protocol (IP) over WPANs, to define the upper layers. IEEE 802.15.5 – Mesh Network. Extension of network coverage without increasing the transmit power or the receiver sensitivity; Enhanced reliability via route redundancy; Easier network configuration – Better device battery life.
802.15.5 provides the architectural framework enabling WPAN devices to promote interoperable, stable, and scalable wireless mesh networking. It is composed of two parts: (i) low-rate WPAN mesh less, which is built on IEEE 802.15.4-2006 MAC, and (ii) high-rate WPAN mesh networks which utilize IEEE 802.15.
3/3b MAC. Common features of both meshes include network initialization, addressing, and multihop unicasting. In addition, the low-rate mesh supports multicasting, reliable broadcasting, portability support, trace route and energy saving function, and the high rate mesh supports multihop time-guaranteed service. XVIII. EEE 802.16 This is a series of wireless broadband standards for broadband for wireless metropolitan area networks.
The 802.16 standard essentially standardizes two aspects of the air interface – the physical layer (PHY) and the media access control (MAC) layer. Covers both OFDM and OFDMA physical layers. OFDM is referred as fixed wimax and OFDMA as mobile wimax. This family of standards covers Fixed and Mobile Broadband Wireless Access methods used to create Wireless Metropolitan Area Networks (WMANs.
) IEEE 802.16-2017 – Draft Standard for Air Interface for Broadband Wireless Access Systems approved by IEEE: The standard promotes early and fast deployment all over the world, of ingenuous and cost reasonable, and interoperable multivendor broadband wireless access products, and encourages competition in broadband access by alternatives provisioning to wireline broadband access, encourages regular and constant worldwide spectrum allocations and speeding up commercialization of broadband wireless access systems. IEEE802.17 Resilient Packet Ring. 802.17 A new ring topology network architecture, called the Resilient Packet Ring (RPR), is standardized to be used primarily in metropolitan & wide area networks.
Fiber optic rings are widely deployed in Metropolitan and Wide Area Networks. Protocols that are neither optimized nor scalable to the demands of packet networks are presently being used by these rings, including speed of deployment, bandwidth allocation & throughput, resistance to faults, & lower equipment and operational costs. The IEEE 802.17 Resilient Packet Ring Working Group defines standards to support the development and deployment of Resilient Packet Ring (RPR) networks in Local, Metropolitan, and Wide Area Networks for resilient and efficient transfer of data packets at rates scalable to many gigabits per second. Existing Physical Layer specifications are built upon by these standards, and new PHYs where appropriate are developed. IEEE 802.17 is a part of the IEEE 802 LAN/MAN Standards Committee. IEEE 802.
17 (RPR) protocol is a ring based network protocol designed for the optimized transport of data traffic over optical fiber ring networks. The design is to provide the resilience found in SONET/SDH networks (50 ms protection) but, provides a packet based transmission instead of setting up circuit oriented connections, aiming to increase the efficiency of Ethernet & IP services. Similar to other IEEE 802 standards, IEEE 802.17 has both a physical and a medium access control (MAC) layer.
An important feature of the physical layer is the use of a dual-ring topology using optical fiber at high data rates, up to 1 Gbps or more. Data can be transmitted simultaneously on both rings in normal operation, doubling the capacity. Robustness is provided by the dual-ring topology by including a capability for automatic reconfiguration after a link failure. The main purpose is to provide enhanced services for the transmission of Ethernet packets over a ring-based interconnect topology at the MAC level. This means a simple mapping from the Ethernet frame format to the RPR frame format. RPR runs on a concept of dual counter rotating rings referred to as ringlets. These ringlets are set up by creating RPR stations at nodes where traffic is supposed to drop, per flow (a flow is the ingress and egress of data traffic).
Media Access Control protocol (MAC) messages to direct the traffic, is used by RPR, which can use either ringlet of the ring. The nodes also negotiate for bandwidth among themselves using fairness algorithms, avoiding congestion & failed spans. Failed spans are avoided by using one of two techniques known as steering & wrapping. All nodes are notified of a topology change & they reroute their traffic if a node or span is broken under steering. The traffic is looped back, in wrapping, at the last node before the break & routed to the destination station.